Russian manned rocketplane. Flown 1945. The LL was a transonic aerodynamic testbed authorized by LII in September 1945. Three were built: the LL-1 with a straight wing; LL-2 with a conventional swept wing; and LL-3 with a forward swept wing.

The LL was towed to a 6 km release altitude by a Tu-2 aircraft. After being cast off, it would fire its Kartukov PRD-1500 solid rocket engine and accelerate to the edge of the sound barrier, with a camera photographing air flow on the tufted wing. The LL-2 was not finished because contemporary fighter programs were already providing data on swept wing configurations. But in 1946 to 1948 the LL-1 flew 30 times and the LL-3 100 times, with test pilots M Ivanov, Amet-Khan Sultan, Anokhin, and Rybko at the controls.

Solid Solid propellants have the fuel and oxidiser embedded in a rubbery matrix. They were developed to a high degree of perfection in the United States in the 1950's and 1960's. In Russia, development was slower, due to a lack of technical leadership in the area and rail handling problems. Solid propellants have the fuel and oxidiser embedded in a rubbery matrix. They were developed to a high degree of perfection in the United States in the 1950's and 1960's. In Russia, development was slower, due to a lack of technical leadership in the area and rail handling problems. More...